Chapter 10- Agriculture Flashcards
CLI
-canada land inventory
-wanted to figure our what resources we have and where they are
Looked at: agriculture land, forestry potential, wildlife, recreation
-quality rated accordingly
How much of Canada’s land mass is agriculture land?
7%
40% of that is marginal or poorer quality
most in South where 90% of population lives
less than 2% is highest quality and we are building houses on this land
chernozenic soil
some of best agriculture soil
-building houses on it
Farming in Canada
- Green Revolution
- Biofuel revolution (corn and soy)
- Livestock revolution (up production due to growth hormones)
- Impact on the global landscape (clearing & massive machinery)
when did agriculture originate
- 9000 to 11000 years ago, shift in demographics with start of agriculture and then the industrial revolution
industrial revolution
-food production increased because 1 person could do the work of an entire family with machines
Agriculture induced changes and increased
- availability of food and feed
- sedentary lifestyles (food storage)
- permanent settlements
- food surpluses
- trade
- conflicts for land (war)
- global populations
- pollution
Green Revolution
worldwide intensification of production
- more output/unit area
- 2x world grain production since 1961
- changed how farming is done
Green Revolution and the Enviro
- began in 1940s
- dramatic increase in yields
- selective breeding
- application of auxiliary energy inputs (use other types of energy to create food)
- mechanization of farming (machines)
- biocide applications (to kill pests)
- war pushed technology change
Auxiliary Energy Flows
2nd law of thermodynamics- loss of energy with longer food chains
-a means to counteract energy loss through the use of: fertilizers
-fossil fuels
0irrigation
0genetics
-biocides
all of these take energy
Agroecosystems
communities of living organisms and the physical resources that sustain them, managed to produce agricultural products
- different species live on agricultural land
- used to do more crop rotation
- monoculture ^risk of whole crop being whipped out
- 10x more energy used for every 1unit of energy produced
Substinence Farming
-can produce 10 food units for every 1 unit of energy used
Sustainable Livlihoods
-each person grows their own food for them
GMOs
- to increase stalled yields in crop yields
- biotechnology & genetic manipulation
- can reduce the use of pesticides
- makes food different than the olden days
GMOs cautions and dangers
- Pleiotrophic effects- unexpected side effects (potential changes in toxins or nutrient content, changes in our genetic makeup)
- Enviro effects- interrupt insect pollination
- disrupt biogeochemical cycles, interbreed with wild relatives, create superweeds - Unintentional Spread- onto lands where they are not intended to grow
- lawsuits, problem with maintaining organic certification
Most Common GMOs
- soybeans
- corn
- cotton
- canola
Why is there still so much poverty?
agriculture gives us 94% of protein and 99% of calories but 20% of people are still malnourished and obesity has tripled
- Canada contributes to world food supply
- due to disproportionate sharing of resources
Effect of agriculture on aquatic ecosystems
- Nutrient losses
- Pesticide Losses
- Sedimentation
- Pathogens
- Wetland drainage
Nutrient losses
Eutrophication- highly productive wetlands dying due to too many nutrients due to fertilizer run off
- can lose surface and ground water
- messes up biogeochemical cycles
Pesticide Losses
- some goes right up into atmosphere
- with wind they get carried away
- runoff and leeching
- goes into the soil
- carried into water bodies
- impacts species that live there
Sedimentation
pollution
- too much sediment can clog gills of fish and suffocate fish eggs
- caused by cattle getting too close to riverbeds
turbidity
foggy, mess up respiration
Pathogens
- pollute drinking water when feces gets into ground water system
- can come into crops by irrigation systems
- contaminating shell fish that take in water
Wetland Drainage
lost 60-70% of wetlands in AB
- too full of nutrients (hypereutrophic)
- many dead wetlands modified by agriculture
- wetlands have a dynamic interface with ground water
Irrigation
largest global use of water
-used in BC to grow grapes and fruit (because the place used to be a desert)
Impact on terrestrial Ecosystems
- Soil Quality
- Biodiversity
- Greenhouse Gases
Soil Quality
- soil blows away if there are not enough nutrients and moisture
- wind and water erosion take soil away
- need organic matter in soil to hold moisture and nutrients
Biodiversity
habitat loss
- plant monocultures
- range land grazing, cover grazing
Greenhouse gases
- affects global warming
- methane
- nitrous oxide (tailpipe fertilizers)
Salinization
excess salt in soil
desertification
degradation of dry land
contamination
herbicides, insecticides
still some DDT contamination
Types of Pesticides
- Insecticide- kill insects (DDT, malathion, carbofuran)
2. Herbicides- kill weeds eg atrazine, 2, 4-D, roundup
Fungicides
hill fungi ex) methyl bromide
Ideal Pesticide
- kills only target species
- breaks down quick with no harm
- no genetic resistance
- cheaper than doing nothing
Benefits of Pesticides
- ^ crop yields
- saves lives (decrease malnutrition)
- live longer ^human health
- ^ profit
- cheaper food cost
- very efficient, works really fast
Pesticide use in the enviro
- genetic resistance
- killing non-target species
- persistence, mobility
- biomagnification
- human health
Alternatives to pesticides
- use better pesticide
- improve cultivation practices
- use natural enemies
- biological control
- birth control (genetically)
- spot spraying
Sustainable Answers
- Integrated Pest Management- minimize yield losses from pests and minimize negative impacts of pest control
- Integrated Plant Nutrient Systems- maximize nutrient use (recycle, N-fixers)
minimize nutrient loss (don’t overtill soil)
-optimize productivity of nutrient flows - No-till conservation agriculture- sow directly (reduce soil impact, maintain permanent plant cover (absorb moisture reduce irrigation), rotate crops, higher yields=lower costs and labours)
- Organic Farming- goals=biodiversity, soil, water, air, less energy, reduce pollution
Organic Farming
Methods- free range
Why grow- ethical, health reasons
Why buy- ethical, help, political, economic
